The 2020 KBC Dublin Marathon has been cancelled due to the coronavirus pandemic.
The race was due to be held on Sunday, 25 October.
Organisers have said all entries for the marathon and the race series will be valid for the 2021 races. For those who do not wish to avail of this, a full refund option is available.
In a statement, race director Jim Aughney said: "We know this is extremely disappointing for all runners, especially those who secured marathon entries.
"We made the difficult decision in the best interest of the health and wellbeing of all those involved in making our events such a success from runners, supporters, volunteers, sponsors, to suppliers. We explored many alternatives for running the events safely but ultimately none were viable."
While elite athletes and regular participants were guaranteed places in the race, organisers switched to a lottery system this year to deal with demand issues.
Details regarding the potential reallocation of lottery places as a result of refunds will be made in early 2021.
As a result of the cancellation, Athletics Ireland has confirmed that the National Marathon Championship, scheduled within the event, has been cancelled.
The announcement means Othmane El Goumri from Morocco will have to wait to defend the title he won in a record-breaking time of two hours, eight minutes and six seconds last October.
Ethiopia's Motu Gedefa clocked 2:27:48 to win the women's race, while Kildare's Patrick Monaghan triumphed in the wheelchair category.
Organisers have hinted at the prospect of staging a virtual race, with details to be revealed in the coming weeks.